Towed vehicle brake controller

ABSTRACT

A brake controller, for controlling the brakes of a towed vehicle, having a control module and a power module is provided. The control module is mounted in the cab of a vehicle used for towing, in such a manner that it can be easily seen and accessed by the driver. The control module is provided with an accelerometer, which can read acceleration forces in at least two axes, and a microprocessor which polls the accelerometer and sends braking information to the power module. The control module is also provided with a gain control, to adjust the amount of brake force information, a manual braking lever and a display panel. The power module, which may be mounted in a convenient location, preferably on the towed vehicle, receives the braking information from the control module and secures power from the towed vehicle to engage its brakes.

FIELD OF THE INVENTION

[0001] The present invention concerns a novel towed vehicle brakecontroller.

BACKGROUND OF THE INVENTION

[0002] Cars, recreational vehicles and light trucks are presently usedto tow other cars or trucks and trailers which are often heavier thanthe towing car or light truck. Towed vehicles can weigh two or threetimes the weight of the towing vehicle and can change the drivingcharacteristics of the vehicle when attached. Presently, there aresystems which can be installed to aid in better controlling a towingvehicle and towed vehicle combination. These systems are designed toallow for the application of brakes on the wheels of the towed vehicles,either with or without the application of the brakes of the towingvehicle, such that the vehicles may be slowed down and/or stopped andthe attitudes of the towed vehicles can be controlled to prevent fishtailing and/or jack-knifing and generally provide for the emergencyapplication of the towed vehicle brakes in the event of separation, orloss of power, from the towing vehicle, known as a breakaway condition.It has been found, however, that the devices of the prior art cannotaccurately determine braking condition due to inherent problems in theirdesigns.

[0003] These prior art systems are divided into two categories based onthe type of braking system used by the towed vehicle. In the case oftowed automobiles (cars and trucks) which are equipped with their ownbraking systems, various types of devices which sense that the towingvehicle is braking and then manually depress the automobile's brakespedal are available. In the case of trailers, which are generallyprovided with electronic braking systems, various types of trailer brakecontrollers which sense that the towing vehicle is braking and then senda control signal back through the towing vehicle to the electric brakesof the trailer are available.

[0004] With respect to towed automobiles, the most common types of brakeassist devices generally tap into the hydraulic brakes or air brakes ofthe towing vehicle. The towed automobile's braking system is connectedto the brake system of the towing vehicle. By connecting the towedvehicle's braking system in this manner means are provided to bothprovide power to the towed automobile's brakes and to cause the brakesto be activated when the towing vehicle's brakes are activated. Thesetypes of systems detect, by noting the change in the brakes of thetowing vehicle, that the towing vehicle is braking and activatemechanical means that push the brake pedal down. It has been found thatthe control provided by this type of system is limited in that thebrakes of the towed vehicle are always applied when the brakes of thetowing vehicle are applied. Independent braking, i.e. braking by thetowed vehicle without braking by the towing vehicle, to assist in thecontrol of the tow situation is generally unavailable.

[0005] Such devices, as the Brake Master and the Toad Stop Vac Brake,allow for the connection of the towed automobile's braking system to theair brakes or vacuum system of a Recreational Vehicle (RV). In thesesystems, a brake pedal depressor, in the form of an air cylinder, isattached to the frame of the towed automobile and clamped to the brakepedal. The air cylinder is connected to the air brakes of the RV suchthat the air from the RV will energize the air cylinder. When the brakesof the RV are activated, air from the RV air brake system is sent to theair cylinder, and to the brake system of the towed vehicle, causing thebrake pedal of the towed vehicle to be depressed. In situations wherethe RV has hydraulic brakes or no vacuum system, an air compressor orvacuum system must be installed in either the RV or in the towedautomobile. With respect to the systems using an air compressor, aregulator must also be installed in the RV. The regulator senses themovement of the brake pedal in the RV and causes the air compressor tosend an appropriate amount of air to the air cylinder, in the towedvehicle, causing the brake pedal of the towed vehicle to be depressed.These installed air systems may also provide the vacuum needed tooperate the automobile's brake system.

[0006] Other towing vehicle-automobile brake system, such as the BrakeBuddy, comprise basically a box with an air cylinder and a plunger whichis placed into the driver area of the towed automobile. These types ofdevices are plugged into the cigarette lighter of the automobile, or areotherwise connected to the automobile's electrical system, while theplunger is clamped to the brake pedal of the towed automobile. Withinthe box, of the device, a pendulum-activated switch and an aircompressor are included. When the pendulum swings so that it activatesthe switch, the air compressor is activated and the plunger pushes thebrake pedal down. These devices are touted as being convenient in thatthey need only be dropped into the towed automobile, plugged in andclamped to the brake without having to be connected to the towingvehicle's brakes or other systems. The accuracy of these devices, indetecting braking situations is questionable in that unless the vehicleis traveling on a level road or running at constant velocity, thependulum switch is subject to misidentifying the swing caused by a slopein the road or a change in velocity as a braking situation. Further, theoperator of the towing vehicle has no control over this device from thetowing vehicle. Any adjustments to the system must be made while bothvehicles are stationary, making accurate adjustments very difficult.Also, these devices operate in vehicles that are not running and,therefore, must use great force to depress the brake pedal. In order tobe effective these devices must be able to produce this amount of forcequickly. Finally, the devices, which comprise means to depress the brakeof an automobile without power assisted brakes, are generally bulky andheavy and are difficult to install and remove. The devices must beremoved in order to operate the towed vehicle independently of thetowing vehicle.

[0007] With respect to devices designed to apply the brakes of trailers,there are presently several controllers that can automatically apply thetrailer's brakes to assist the driver of the towing vehicle. Sincetrailer brakes are generally electronically activated it has been foundthat means can be used to determine the degree to which the towingvehicle is slowing and translate that information so that the brakes ofthe trailer may be applied. These controllers generally take the form ofa box, housing all of the electronics including the means to determinethat the towing vehicle is braking and the degree to which it isbraking, and a power amplifier to send electricity to the trailer'sbrakes to accomplish braking. These prior art trailer brake controller,further, generally, comprise a control panel which allows the user tomanually control braking, adjust the amount of braking and provide somemaintenance, such as leveling of the device. The control panel of abrake control device also generally has a light display to indicate thedegree of braking power.

[0008] It has been found that these trailer brake controllers aregenerally too large and bulky to be installed in such a manner that thecontrol panel can be both seen by the driver and reached by the driver.Since the controller must be accessible to the driver of the vehicle,the controllers are generally mounted under the towing vehicle's dashboard so that the controls can be reached. Although such mounting allowsthe driver to reach the controller, it generally places the controllerout of the direct sight of the driver. Further, the driver must usuallytake his hand from either the steering wheel or the gear shift lever ofthe vehicle to operate the controller. To allow the driver to see thecontrol panel while reaching the controls, when possible, thesecontrollers have been mounted along a vertical wall of the dash boardsof some vehicles. While this allows for a better view of the controller,such mounting has generally been found to take the device out of levelor cause the device to have limited brake sensing abilities.

[0009] Trailer brake controllers typically are electrically connected tothe power source of the towing vehicle, to the brake lights of thetowing vehicle (as a means of detecting braking) and to the brakes ofthe towed vehicle. In connecting a trailer brake controller, heavy gaugewires have been used to carry power from the battery to the controllerand amplified power from the controller to the brakes. Typically thereis a battery wire (a large positive), a large wire going to the brakes,and some slightly smaller wires for ground and for the brake lightsignal. These controllers effectively take power from the battery,amplify it, and apply it to the trailer's brakes. Thus relatively highcurrent from the towing vehicle is carried from the battery of thetowing vehicle through the controller and back to the towed vehicle.Heavy gauge wire has been used in these devices as power from the carbattery must be taken to the cab of the towing vehicle, amplified (toprovide generally 2.5 amps of power to each trailer brake) by thecontroller, and then taken back through the entire length of the towingvehicle to each of the towed vehicle's brakes. It has been found thatthe distance from the controller to the brakes of the towed vehicle is asource of resistance and loss of electrical energy.

[0010] Further, in trailer brake controllers of the prior art,electrical power is continuously provided between the towing vehicle andthe towed vehicle so that it can be available immediately. Thus, when atrailer is not attached to a vehicle in which a trailer brake controllerhas been installed, the trailer brake controller continues to provideelectricity to the wires that energize the braking system providingelectricity to the open hitch socket plug. This situation not onlycreates the hazard of electrical shock, it has also been found that theexposure of the electrically charged socket plug, of the trailer hitch,to the atmosphere causes the connectors within the plug to more rapidlyoxidize adding to the electrical resistance in the system. As a result,trailers with large number of brakes often cannot be supplied with allof the power needed for braking.

[0011] Presently, the most popular types of trailer brake controldevices are proportional controllers and digital controllers.Proportional controllers generally use a dynamic accelerometer in theform of a pendulum that measures the force of braking, or deceleration,in the towing vehicle and applies the towed vehicle's brakesaccordingly. The pendulum, which generally swings in the plane of theaxis of motion of the towing vehicle, measures force by the degree ofswing, from a default position, which the application of the towingvehicle's brakes causes in the pendulum. A greater swing by the pendulumwould denote a greater urgency in braking and the proportionalcontroller responds by greater application of the brakes. Pendulum basedsystems lose reliability when the device is not initially leveled, losesits level, or if the device, due to road conditions, slope of the road,etc. is not correctly level at the time of use. All pendulum baseddevices must be maintained level in order to operate effectively. It hasbeen found that few of these systems maintain level and often, thesesystems are never level, even at the time of their installation. It hasalso been found that mounting these controllers along a vertical wall ofthe dash board of the vehicle limits the swing of the pendulum to suchan extent that accurate measurement of braking may be greatlycompromised.

[0012] Digital controllers do not use a pendulum to measure the force ofbraking. Instead digital devices provide braking by sensing the amountof time that the towing vehicle's brakes are applied and applying brakeson the towed vehicle accordingly. Since the amount of time a brake isapplied is indicative of the force needed to stop the vehicle, digitalcontrollers use brake time as the means of determining the braking needsof the towed vehicle. When the driver of the towing vehicle presses thebrake pedal down for a long period of time, the digital controllerinterprets this to indicate the need for greater braking power in thetrailer. Conversely, holding the pedal down for a small amount of timeis interpreted as a need for a small amount of brake force in thetrailer. Digital controllers can sense the amount of braking in thetowing vehicle through connection to brake components of the towingvehicle. The components, to which such sensors can be connected, includethe brake lights, the brake pedal or hydraulic brake lines of the towingvehicle. When the digital controller senses that the brakes have beenapplied, the sensors determine the amount of braking applied and applythe brakes of the towed vehicle. This manner of acquiring brakinginformation has been found to be unreliable as brake components caneasily lose adjustment, react differently in different weather or roadconditions and may not provide reproducible results each time they areread by the controller.

[0013] Digital controllers generally are provided with a component, suchas a gain control knob, that enables the operator to provide a delay ofgenerally between two and twelve seconds for the brake controller torespond to the braking of the towing vehicle. The operator may makeadjustments that cause the brakes of the towed vehicle to respond in adesired manner. A delay in the towed vehicle's braking may be desired indifferent types of traffic and weather situations when the applicationof the towed vehicle's brakes in response to a quick application of thetowing vehicle's brakes may be unnecessary or dangerous. It has beenfound however, that a delay of even two seconds in a panic stopsituation with a heavy towed vehicle may be dangerous.

[0014] Both the proportional and digital controllers are generallyprovided with manual controls, allowing the driver to apply the towedvehicle brakes with, for example, a slide bar or lever. However, as bothtypes of devices must generally be mounted under the dashboard, inemergency situations, manual control of braking may cause the dangeroussituation of the driver removing his hands from the steering wheel ortaking his eyes off of the road. Further, braking can often times beassisted by use of the vehicle's engine and transmission bydownshifting. However, if the driver must reach down to control thebrakes of the towed vehicle he must either take his hands off of thesteering wheel of the vehicle or off of the gear shift controller.

[0015] One manufacturer of trailer brake controllers has included a joystick device that allows the user to manually apply the trailer brakesthrough a wired remote control connected to one of the types ofcontrollers described above. This device, the Hayes Wheels Micro ControlHD Plus, when used with the optional “Manual Remote”, allows theoperator to manually apply the trailer brakes by holding the joy stickand pressing a button. However, the device does not comprise any meansfor sensing the need for brakes or for providing information concerningcurrent braking conditions to the driver. Instead it is merely a manualbraking slide control similar to the manual slide controls on otherprior art trailer brake controllers. Further, the driver must have thejoy stick in his hand or near his hand in order to be able to use thejoy stick.

[0016] In another towing vehicle-trailer braking system, the UltimaBraking System, a sensor for determining the degree to which the towingvehicle's brake pedal is depressed is provided. The sensor causes anelectrical signal to be sent to the trailer brakes. The sensor comprisesa displacement sensitive manual control module that is mounted to thebrake arm of the towing vehicle. Braking information is sent to thedisplay module which is mounted in a convenient location in the cab ofthe towing vehicle. Adjustments to the manual control module may be madeusing the display module. However, the display module contains noinertia activated components and no pendulum. Although a display isprovided in a viewable position, the device has all of the othershortcomings discussed with respect to other prior art proportionalcontrollers, including the need to continually synchronize the brakes ofthe towed and towing vehicles.

[0017] We have invented a novel brake controller which can be used withboth towed trailers and towed automobiles. Our invention allows thedriver of the towed vehicle to view the display panel of a controllerand have access to the manual brake controls provided. In our invention,the controller accurately determines the existence of a brakingsituation and sends a signal to a separate power module, which may beinstalled in the towed vehicle, to provide drivers to supply power tothe brakes of the towed vehicle as needed. Our invention allows theseparate power module to be connected to the power source of the towedvehicle so that power is not lost between the front of the towingvehicle and the towed vehicle brakes.

[0018] It is therefore an object of the present invention to provide ameans to mount a control apparatus comfortably in the cab of a towingvehicle so that the brakes of a towed vehicle may be controlledaccurately and without the driver having to take his eyes off the roadto use the controller.

[0019] It is another object of the present invention to provide atrailer brake control device that accurately measures the decelerationof the towing vehicle and translates and causes the brakes of the towedvehicle to be applied correctly.

[0020] It is a further object of the present invention to provide atrailer brake controller that has a power module mounted closer to or onthe towed vehicle so that electrical energy loss, due to resistance, islessened.

[0021] It is a further object of the present invention to provide apower module which activates the brakes of the towed vehicle only whenneeded such that electrical energy need not be continuously providedbetween the towing vehicle and the towed vehicle.

[0022] It is a further object of the present invention to provide abrake system controller that can control the brakes of a towed car ortruck using means to accurately measure the deceleration of the towingvehicle, translating those measurements and applying the towed vehicle'sbrakes accordingly.

[0023] It is a further object to provide a brake controller for use witha towed automobile that causes the brakes of the towed automobile to becontrolled accurately by means of measurement of the braking forces onthe towing vehicle and by manual means.

[0024] It is a further object of the present invention to provide acontrol module for a brake controller that can be used on both trailerand towed automobile systems.

[0025] Other objects and advantages of the present invention will becomeapparent as the description proceeds.

SUMMARY OF THE INVENTION

[0026] In accordance with the present invention, a brake controller isprovided, for use with a towing vehicle when the towing vehicle is inassociation with a towed vehicle. In an illustrative embodiment, thebrake controller comprises a control module for location within the cabof the towing vehicle and comprising a user interface with gain andmanual braking controls and automatic braking sensors. A power module isprovided, separate from said remote control module, comprising powerdrivers for supplying power to activate the brakes of the towed vehicle.The control module is connected to the power module such that when thecontrol module is activated the power drivers of the separate powermodule operate to activate the brakes of the towed vehicle.

[0027] In the preferred embodiment of the invention, the control moduleis mounted in a location convenient to the driver of a towing vehicle,such as on the gear shift lever or on the dashboard of the towingvehicle. In this manner control of a towed vehicle's brakes can bemaintained comfortably by the driver with his eyes on the road and atleast one hand on the steering wheel while having the other the otherhand available for shifting gears or manipulating the controls of thebrake control module. With the control module so mounted, the powermodule may be connected anywhere in or on the towing vehicle or in or onthe towed vehicle, such that it can derive the power needed to applybrakes from the power source of the towing or towed vehicle. As thepower module takes power from the towed vehicle, communication betweenthe control module and the power module may be made using relativelylight gauge wire.

[0028] In the preferred embodiment, the control module comprises amanual brake lever and a gain control knob and automatic brakingsensors, including a multi-axis accelerometer and a microprocessor, thatproduce braking signals which are sent to the power module. In thepreferred embodiment, a dual accelerometer is used, however, it is to beunderstood that the term “multi-axis accelerometer” includes allaccelerometers that sense force on at least two axes. As theaccelerometer senses forces in at least two axes of movement of thetowing vehicle, leveling of the brake controller is not necessary. Themicroprocessor is connected to the braking system of the towing vehicle,preferably through its brake lights. The microprocessor is alsoconnected to the manual brake lever, the gain control knob and theaccelerometer of the controller, and a power source in the towingvehicle.

[0029] In one embodiment, the microprocessor continually polls theaccelerometer to determine instantaneous acceleration forces on thetowing vehicle. When the brakes of the towing vehicle are engaged, itsbrake lights are lit sending a signal to the microprocessor. Themicroprocessor sets its previous reading of the accelerometer as a baseand computes the change in forces therefrom, generating a brakingsignal, preferably in the form of a pulse modulated signal, which issent to the power module.

[0030] In the preferred embodiment, the power module comprises powerdrivers, signal receivers, a microprocessor and power amplificationmeans. Upon receipt of a braking signal from the control module, thepower module compares the signal to acceptable braking signals. If thepresent signal is a true braking signal, the power module cause thepower drivers and amplification means to produce braking power for thetowed vehicle.

[0031] The preferred embodiments of the present invention are designedfor operation in situations where the towed vehicle is an automobile,having its own power braking systems, and in a trailers havingelectronic brakes.

[0032] A more detailed explanation of the invention is provided in thefollowing description and claims and is illustrated in the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 is a schematic diagram, including a perspective view of aremote control module, of a brake control system in accordance with theprinciples of the present invention.

[0034]FIG. 2 is a schematic diagram, including a perspective view of aremote control module, of a trailer brake control system in accordancewith the principles of the present invention.

[0035]FIG. 3 is an electrical schematic diagram of a control module andaccelerometer in accordance with the principles of the presentinvention.

[0036]FIG. 4 is an electrical schematic diagram of an accelerometer inaccordance with the principles of the present invention.

[0037]FIG. 5 is an electrical schematic diagram of a car brake systempower module in accordance with the principles of the present invention.

[0038]FIG. 6 is an electrical schematic diagram of a trailer brakesystem power module in accordance with the principles of the presentinvention.

[0039]FIG. 7 is an electrical schematic diagram of a gain controlcircuit in accordance with the principles of the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

[0040] Referring to the drawings, FIG. 1 shows a wired remote controlmodule 10 constructed in accordance with the principles of the presentinvention and illustrates a control module 10 of a system in which atowing vehicle is towing an automobile having an independent brakingsystem. For clarity in FIG. 1, those parts of the present inventionwhich in a preferred embodiment are housed in the towing vehicle areshown in box 2 and those part of the present invention that are housedin the towed vehicle are shown in box 4.

[0041] Control module 10 is shown attached to a gear shift lever of atowing vehicle. It is to be understood, however, that control module 10may be attached to any convenient location within the passengercompartment of the towing vehicle, such as on the vehicle's dashboard.Control module 10 comprises a housing 14, gain control knob 16, a manualcontrol lever 18, and a lighted display panel 20. Lighted display panel20 may include brake force light emitting diodes (LEDs) display 22 thatshow the braking force being applied to the towed vehicles brakes, and astatus LED 24 that indicates system status. Control module 10 furthercomprises a microprocessor, an accelerometer, a buzzer (or other audioalert device) and circuitry that will be discussed below. Control module10 works with a power module, shown as power module 50 in FIG. 1 andpower module 92 in FIG. 2. In the preferred embodiments, control module10 is physically separate from the power module.

[0042]FIG. 1 shows that control module 10 is coupled, within the towingvehicle, to a line 30 having a ground line 32, ignition line 34, a brakelight line 36 and a control line 38. These lines are then connected toone half of a pin and socket connector 40 for ease of connection to aground, braking lights and ignition switch of the towing vehicle, whichlines are wired to the other half of pin and socket connector 40.

[0043] As will be described in greater detail below, when control module10 is installed in the vehicle, ignition line 34 provides power tocontrol module 10, brake light line 36 provides a determination thatbraking is occurring, ground line 32 provides the necessary ground forthe system and control line 38 provides connection of the control module10 to the braking system of the towed vehicle.

[0044] Ground line 32, ignition line 34, brake light line 36 and controlline 38 may comprise light gauge wire, or “control wire”, preferably 18gauge. Control line 38 may be replaced with a signal transmissionsystem, such as an RF, infrared, ultrasonic or other signal transmitter,without departing from the novel scope of the present invention. Thecontrol line 38 is coupled through a hitch socket plug 42 with side 42 aon the towing vehicle and side 42 b on the towed vehicle. It is to beunderstood that hitch socket plug may be of a conventional type, used toconnect brake light and turn signal indicator systems, as well as priorart brake control systems, between towing and towed vehicles.

[0045] The socket plug 42 b is coupled through control line 38 to apower module 50, through a control input 52. Power module 50 may bemounted in any convenient place, in the towing vehicle-towed vehiclecombination, without departing from the novel scope of the presentinvention. For example, power module 50 may be mounted in the towingvehicle or in the towed vehicle. Control line 38 is connected to powermodule 50 using conventional means such as a connector 54. Power module50 produces, in a manner described in greater detail below, a statussignal which it returns to control module 10 and status LED 24 throughcontrol line 38. While the system is working, LED 24 glows on controlmodule 10.

[0046] Power module 50 further comprises a breakaway switch input 56. Abreakaway switch 58 is connected to switch input 56 on power module 50,through socket connector 54. A lanyard 60 is attached between the towingvehicle and the breakaway switch 58 on the towed vehicle such thatshould the vehicles separate, lanyard 60 will rupture breakaway switch58 causing breakaway switch 56 to be actuated. The results of theactuation of breakaway switch 56 will be discussed in greater detailbelow.

[0047] Power module 50 further comprises brake light switch controllines 62 and 64. Lines 62 and 64 are used to interrupt the brake lightswitch signal for the car being towed, as will be discussed in greaterdetail below. Inputs 52 and 56 are relatively low power signal lines anddo not require heavy gauge wire.

[0048] Power module 50 comprises a battery connection output 66, fromwhich the battery of the towed vehicle (not shown) is connected tocircuit breaker 68 of the towed vehicle via line 70. A vacuum pumpoutput 72 is connected, via line 74, to a vacuum pump 76 supplied to thetowed vehicle. A ground input 78 is provided on power module 50 andappropriate grounding is provided via line 80. An actuator output 82 isprovided on power module 50 and is connected, via line 84 and pin andsocket connection 85, to an actuator 86 provided on the towed vehicle.It is to be understood that actuator 86 may take the form of a solenoid,gear motor, air cylinder, hydraulic cylinder or other type of actuatingdevice which can provide the necessary force to cause the brake pedal ofan automobile to be depressed, without departing from the novel scope ofthe invention. In one of the preferred embodiments of the presentinvention, actuator 86 is a solenoid. Vacuum pump 76 provides the vacuumneeded to run a power braking system while the automobile's own systemis turned off. Actuator 86 operates the brakes of a towed automobile byproviding the force necessary to depress the brake pedal of anautomobile. While a pin and socket connection 85 is illustrated anddescribed, any conventional means of connection between line 84 andactuator 86 may be used without departing from the novel scope of theinvention. Actuator 86 is powered by the battery of the towed vehiclethrough circuit breaker 68 via line 88 which is connected to pin andsocket connection 85. Lines 70, 74, 80 and 84, which are preferably ofheavy gauge wire, such as 10 gauge wire, are connected to power module50 through conventional means-such as ¼ inch insulated tabs 90. Line 88may also be comprised of heavy gauge wire. Power module 50 produces, ina manner described in greater detail below, a status signal which itreturns to control module 10 and status LED 24 through control line 38.The absence of the status signal is a warning to the operator of thetowing vehicle that a problem, such a separation of the vehicles, hasoccurred. The operation of power module 50 will be described in greaterdetail below.

[0049]FIG. 2 shows the remote braking system of the present inventionwhere a vehicle is towing a trailer, having electronic brakes, ascontrasted to towing an automobile as in FIG. 1. For clarity in FIG. 2,those parts of the present invention which in a preferred embodiment arehoused in the towing vehicle are shown in box 2 and those part of thepresent invention that are housed in the towed vehicle are shown in box4.

[0050] Referring to FIG. 2, control module 10 is identical to thecontrol module 10 of FIG. 1 and is coupled to the towed vehicle in amanner similar to that shown in FIG. 1. It will be seen, however, thatpower module 92 and the manner in which it is connected in the “trailer”system is different.

[0051]FIG. 2 shows control line 38 coupled, through hitch socket 42 b,to power module 92 at control input 94. Control line 38 is connected topower module 92 using conventional means such as connector 96. Powermodule 92 produces, in a manner described in greater detail below, astatus signal which it returns to control module 10 and status LED 24through control line 38. Power module 92 further comprises a breakawayswitch input 98 connected to breakaway switch 100. Breakaway switch 100is coupled via line 102 to circuit breaker 104, which is connected tothe battery of the trailer, and operates similarly to switch 58described above. Power module 92 further comprises power input 106 whichis connected to the trailer battery via line 108 through circuit breaker104.

[0052] Power module 92 comprises several power outputs, utilizingheavier gauge wire connectors due to the high currents produced as aresult of the operation of power module 92. A ground output 110 isprovided on power module 92 and appropriate grounding is provided vialine 112. Brake power output 114 is connected, via line to the brakemagnets of the trailer through line 116. When the microprocessorreceives a braking signal from control module 10, it sends a signal tobrake power output 114 which operates the brake magnets of the trailer.The brake magnets are conventional commercially available brake magnets,commonly used on trailers.

[0053] The sensing of a braking situation in both the towed vehicle andtrailer system and the towed vehicle and towed automobile system isidentical. In the operation of the system, a braking event results fromeither a signal being received from the brake light line 36, i.e. as aresult of the activation of the brakes in the towing vehicle (whichwould cause the brake lights of the towing vehicle to light) or by themanual braking lever 18 being actuated by the driver of the towingvehicle. Either of these events will cause a braking signal on controlline 38. The braking signal is a pulse width modulated signal which iseither proportional to the amount of braking that is sensed or isproportional to the degree to which the manual brake lever 18 isdepressed. The manner in which the braking signal is generated will nowbe described.

[0054] Referring to FIG. 3, a schematic diagram of a control module 10in accordance with the present invention is shown. Control module 10 hasinputs for each of its components shown in FIG. 1 and FIG. 2. Amicroprocessor 118 and an accelerometer 212 are provided within controlmodule 10. The accelerometer 212 of the present invention is preferablyof a type that can read forces in more than one axis. In theillustrative embodiment, a mult-axis accelerometer is used. Such anaccelerometer allows the mounting of the control module without the needfor leveling the device. In the illustrative embodiment, a dual axisaccelerometer is used. The dual axis accelerometer determines the forceof braking, i.e. acceleration, in two axes, e.g. the x and y axes, andsums the acceleration in the x direction with the acceleration in the ydirection to determine the total acceleration. This information isprovided to the microprocessor 118 so that a braking signal can begenerated.

[0055] An ignition hookup pin 120 is connected to diode 122 thatprovides reverse polarity protection and is connected to currentlimiting resistor 124 which supplies the operating voltage to thevoltage regulator 126. Voltage regulator 126 generates a 5 volt outputthat is fed to microprocessor pin 128 and microprocessor pin 130. The 5volt line 132 also provides power through resistor 134 to accelerometerpin 138. A ground signal is on pin 121 of the control module thatprovides a ground return path for all of the voltages used in thecontrol module.

[0056] Resistor 124 is also connected to a metal oxide varistor 125 thatis connected to ground for surge protection. The voltage line continuesand connects to capacitor 127. The other side of capacitor 127 goes toground. The voltage regulator 126 reference is referenced to ground.

[0057] Control module 10 further comprises an adjustment potentiometer140 that connects to microprocessor pin 142. Potentiometer 140 is usedto set the amount of gain, using gain knob 16 (FIGS. 1 and 2). Thevoltage for the potentiometer comes from the 5 volt regulator and groundand potentiometer 140 generates a voltage proportional to its position.The voltage generated is sent to pin 142 of microprocessor 118. Theadjustment of gain allows the driver to adjust the amount of brake forceto be applied. The higher the gain is set the more braking force isapplied for a given braking situation. In city driving, gain may be keptlow as speeds and conditions warrant less braking force. One may alsoraise the gain to compensate for having a heavy load, for example, whena the towed vehicle is large or is carrying a heavy load.

[0058] Potentiometer 144 is used to connect the 5 volt power supply andground to generate a voltage level proportional to the position of themanual brake lever 18 (FIGS. 1 and 2). The voltage level from the manualbrake lever 18 is sent to pin 146 of microprocessor 118. Brake lightline 36 is connected to brake light pin 148 of control module 10. Thebrake light signal, generated in the towing vehicle, goes throughresistor 150. Zener diode 152, which is connected to resistor 150, isused for voltage translation and noise protection. Brake line pin 148 iscoupled to pin 152 of microprocessor 118 through resistor 154. Resistor154 pulls the line to ground in the event that there is no connectionbetween the brake lights of the towing vehicle and brake line pin 148.

[0059] Pin 155 of control module 10 is the control line 38 output of thecontrol module 10. It is coupled to a positive temperature coefficient(PTC) thermistor 156 as a protection device to prevent overcurrent fromdamaging any of the circuitry in control module 10. The PTC thermistor156 is coupled to the collector 158 of transistor 160. The base 162 oftransistor 160 is connected to resistor 164, which connects to pin 166of microprocessor 118. This line 167 is used to generate the controlsignal coming from control module 10. Also connected to PTC thermistor156 is a line 168, connected to resistor 170, that is connected to zenerdiode 172 that is connected to ground for voltage translation and noiseprotection. The cathode of zener diode 172 is connected to resistor 174which is connected to ground to pull the signal down in the event of nosignal on control line 38 (pin 155). The signal is fed to pin 176 ofmicroprocessor 118. On pin 178 of microprocessor 118 a signal isgenerated that controls a buzzer 180, within control module 10, thatprovides an audible alert for certain condition concerning the status ofthe system as described below.

[0060] Pin 182 of microprocessor 118 connects to a current limitingresistor 184 that connects to a light emitting diode (LED) 186. LED 186is the status LED 24 of FIGS. 1 and 2. Pin 188 of microprocessor 118connects to a current limiting resistor 190 which is connected to LED192. LED 192 is a braking level indicator. Pin 194 of microprocessor 118is connected to current limiting resistor 196 which is connected to LED198 which is a braking level indicator. Pin 200 of microprocessor 118 isconnected to current limiting resistor 202 which is connected to LED 204which is a braking level indicator. Pin 206 of microprocessor 118 isconnected to current limiting resistor 208 which is connected to LED 210which is a braking level indicator. LEDs 192, 198, 204 and 210 form LEDdisplay 22 of FIGS. 1 and 2. In the operation of the system the numberof braking level indicators that are lighted is an indication of brakingforce.

[0061]FIG. 3 shows an accelerometer 212, which is shown in greaterdetail in FIG. 4, in the form of an integrated circuit. Pin 214 ofmicroprocessor 118 is an input connection reading the accelerometer 212.Pin 214 connects to the Y-axis data output 216 that is filtered throughcapacitor 218 through the accelerometer 212. Pin 220 of microprocessor118 is an input connection reading the G-force sensor of accelerometer212. Pin 220 connects to the X-axis data output 222 that is filteredthrough capacitor 224 connected to ground. The accelerometer integratedcircuit 212 has a resistor 226 that sets the oscillator frequency thatis connected in between pin 228 and ground.

[0062] Referring to FIG. 4, accelerometer 212 has a power supply input232 that is connected to resistor 134. Resistor 134 works as a filterelement to the power supply to pin 138 of the accelerometer 212integrated circuit. This line 234 is also connected to the capacitor236. The other side of 236 connects to the ground pin 238 and to theground pin 121 of the control module 10. Ground 238 connects to resistor226. The other side of resistor 226 connects to pin 228 of theaccelerometer 212 to set the operating frequency on the internaloscillator. Pin 240, which is the Y-axis data output, of accelerometer212, connects to pin 216 of the accelerometer 212 and also to capacitor218. Capacitor 218 connects to ground for low pass filtering of theY-axis. Pin 244 which is the X-axis data output, connects to the pin 222of accelerometer 212 and also to capacitor 224 which is connected toground for low pass filtering of the X-axis.

[0063]FIG. 5 is a schematic circuit diagram of the towed automobilebrake power module 50 and FIG. 6 is a schematic circuit diagram of thetrailer brake power module 92. The control signal generated in controlmodule 10 is received in the power module 50, or the power module 92,and, if the signal is determined to be within the braking parametersprogrammed into the system, the power modules 50, 92 cause theappropriate braking power to be generated and applied. The controlsignal is in the form of codes, and in the illustrative embodiment thecodes comprise variable duty cycles, such as pulse width modulated dutycycles.

[0064] Referring to FIG. 5, the towed car brake power module 50 has abattery line input 66. Battery line input 66 connects to resistor 250and also to relay 252. Relay 252 continues as an output to vacuum pumpoutput 72. The other side of resistor 250 connects to the anode of diode254, and the cathode of diode 254 continues to be the 12 volt powersupply for the brake module 50. The maximum voltage for brake module 50is limited by metal oxide varistor 256 which is connected to ground onground output 78. Relay 252 is connected to output of diode 254 12 voltsupply and also to the cathode of diode 258. The anode of diode 258connects to the other side of the coil of relay 252 which is connectedto the collector of transistor 260. The emitter of transistor 260connects to ground. The base of transistor 260 connects to resistor 262.The other side of resistor 262 connects to an output on microprocessor264. The 12 volt supply coming from the cathode of diode 254 connects toresistor 266. The other side of resistor 266 connects to the positiveplate of capacitor 268. The negative plate of capacitor 268 goes toground. The positive plate of capacitor 268 is also connected to theinput of voltage regulator 270. Voltage regulator 270 connects itsreference to ground and has a 5 volt output that connects to capacitor272 and capacitor 274. The negative plates of capacitor 272 andcapacitor 274 connect to ground and also the ground of microprocessor264. The positive plates of capacitor 272 and capacitor 274 connect tothe positive pin of microprocessor 264, to the reset pin ofmicroprocessor 264 and to resistor 276. The other side of resistor 276connects to thermistor 278 and also to an input pin of microprocessor264. The other side of thermistor 278 connects to ground.

[0065] Breakaway switch input 56 connects to resistor 280, and the otherside of resistor 280 connects to the 12 volt supply. Input 56 connectsto resistor 282, and the other side of resistor 282 connects to thecathode of zener diode 284 which is connected to ground. This linecontinues to an input pin of microprocessor 264. Control input 52connects to resistor 286, and the other side of resistor 286 connects tothe 12 volt supply. Control input 52 connects to resistor 288, the otherside of resistor 288 connects to the cathode of zener diode 290. Theother side of zener diode 290 connects to ground and the line continuesto an input pin of microprocessor 264. Brake light switch control line64 connects to the normally closed pin of relay 292. The common pincontact of relay 292 connects to brake light control line 62. One sideof the coil of relay 292 connects to the 12 volt supply and to thecathode of diode 294. The other side of the coil of relay 292 and theanode of diode 294 connect to the collector of transistor 296. Theemitter of transistor 296 connects to ground. The base of transistor 296connects to resistor 298. The other side of resistor 298 connects to anoutput of microprocessor 264. An output 299 of microprocessor 264connects to resistor 300, which connects to the gate of transistor 302.Resistor 300 also connects to resistor 302. The other side of resistor302 connects to the gate of transistor 304. The output 299 also connectsresistor 306. The other side of resistor 306 is connected to ground. Thesource pins of transistor 302 and transistor 304 are connected toground. The drain pins of transistor 302 and transistor 304 areconnected together and connected to actuator output 82 and is alsoconnected to the anode of diode 308. The cathode of diode 308 connectsto the battery connection of the control module.

[0066] Thermistor 278 is closely coupled to transistor 302 andtransistor 304 to sense temperature. While the sensing of thetemperature controls the maximum duty cycle to limit the maximumtemperature of the transistors. This pulse width modulation techniquewill prevent damage to the power module device as well as to theactuator it is driving. The heating of the output transistor is matchedto the heating of the actuator. This is done by using transistor devicesthat heat up proportionally to the heating up of the actuators.

[0067] Referring to FIG. 6, the power input 106 of trailer brake powermodule 92 connects to resistor 310 and also connects to resistor 312.The other side of resistor 312 connects to the brake power output 114 ofpower module 92. Power input 106 also connects to the drain oftransistor 314, and the source of transistor 314 also connects to brakepower output 114. The gate of transistor 314 connects to driverintegrated circuit 316. Brake power output 314 is also connected todriver integrated circuit 316. The other side of resistor 310 isconnected to the anode of diode 318, the cathode of diode 318 connectsto the 12 volt power source and connects to driver integrated circuit316 and the capacitor 320 positive plate. Capacitor 320 connects, viaits the negative plate, to ground and to the driver integrated circuit316. The 12 volt supply also connects to the cathode of zener diode 322,and the anode of zener diode 322 connects to ground output 110 of powercontrol module 92.

[0068] A microprocessor 324 is provided in power module 92. The 12 voltpower supply line from the cathode of diode 318 also connects to themicroprocessor power supply input pin 326 and also to resistor 328. Theother side of resistor 328 connects to an input pin of microprocessor324 and also to thermistor 330. The other side of thermistor 330connects to ground.

[0069] Control input 94 connects to positive temperature coefficient(PTC) thermistor 332. The other side of the PTC thermistor 332 connectsto resistor 334. The other side of resistor 334 connects to the 12 voltsupply. The output of PTC thermistor 332 connects to resistor 336, whichperforms a level translation filtering of the control signal. The otherside of resistor 336 connects to the cathode of zener diode 338; theanode of zener diode 338 connects to ground. The signal on the cathodeof zener diode 338 connects to capacitor 340 for filtering of thecontrol signal; the other side of capacitor 340 connects to ground. Thepositive side of cathode 340 connects to an input pin of microprocessor324.

[0070] Another connection from the output of PTC thermistor 332 connectsto the collector of transistor 342. The emitter of transistor 342 goesto ground while the base of transistor 342 goes to resistor 346. Theother side of resistor 346 goes to an output on microprocessor 324.Transistor 342 is used to shunt the control signal upon the absence of abrake magnet presence. Breakaway switch input 98 connects to resistor348. The other side of resistor 348 connects to resistor 350, whichconnects to ground, and connects to the cathode of zener diode 352,while the anode of zener diode 352 connects to ground. Breakaway switchinput 98 also connects, through resistor 348 to the positive plate ofcapacitor 354, the negative plate of capacitor 354 connects to groundand the connection continues to an input pin of microprocessor 324. Thiscircuit performs the breakaway input control.

[0071] Transistor 314 is used to switch the braking magnets on and offas a function of the control signal coming into power module 92.Resistor 312 is used to deliver current to the brake magnets and is usedto determine if the brake magnets are present.

[0072] Brake power output 114 is connected to resistor 356, the otherside of resistor 356 is connected to resistor 358 which is connected toground, to form a voltage divider to feed the signal to an input pin 359on microprocessor 324 to determine if the brake's magnets are present.The cathode of diode 362 is connected to an input pin of microprocessor92 and to capacitor 360. The anode of diode 360 and the negative plateof capacitor 362 are connected to ground. This provides the inputvoltage translation and filtering for a brake magnet detectioncircuitry.

[0073] Thermistor 330 is closely coupled to transistor 314 to sensetemperature. While the sensing of the temperature controls the maximumduty cycle to limit the maximum temperature of the transistors. Thispulse width modulation technique will prevent damage to the power moduledevice.

[0074] Referring to FIG. 7, the gain control circuit signal isoriginated from a gain control potentiometer 140, that is connectedbetween a 5 volt supply and ground. A proportional output voltage of therotation of potentiometer 140 goes to a buffer amplifier input 370; theoutput goes to a summing circuit 372. The voltage output of gain controlpotentiometer 140 also goes to the voltage control input of a one shot,or voltage controlled monostable multivibrator 374. The voltage controlinput determines the pulse width output upon triggering. The one shot374 output is also connected to the summing circuit 372 with the outputof buffer amplifier 370. In addition, the output of the gain control 140voltage goes to a variable gain control input pin of a variable gainamplifier 376. The variable gain amplifier 376 gets its signal fromaccelerometer 212. The signal from accelerometer 212 goes to the inputof buffer 378. The output of buffer 378 connects to a low pass filter380 and the output of low pass filter 380 goes to the input of variablegain amplifier 376. The output of the variable gain amplifier 376 goesto summing circuit 372.

[0075] The output of the summing circuit 372 goes to transmission gate382, the output of transmission gate 382 goes to the voltage control ofthe pulse width modulator circuit 384, which also has resistor 386 whichis connected to ground. The input of pulse width modulated circuit 384is zero volts when transmission gate 382 is open. The output of thepulse width modulator 384 is the control signal on line 38 of FIGS. 1and 2.

[0076] Brake light line 36 is connected to the trigger of the voltagecontrol one shot 374 so that when the brake light signal becomes activeit initiates a pulse width proportional on the voltage control pin. Thebrake light signal also continues to the control of the transmissiongate 382 that enables the pulse width modulator 384 to receive thesignal from the summing circuits.

[0077] The overall circuit works where the gain control resistor 140generates a voltage from the position of the rotation of thepotentiometer. The DC output voltage goes and generates a static amountof gain or constant pulse width generated by the pulse width modulator384 when the brake light is enabled and which is summed with theduration of the one shot 374 that gives it a maximum pulse width or 100%duty cycle for the duration of the one shot 374 pulse and it is alsosummed with accelerometer 212 whose output of the accelerometer 212 isamplified by the variable gain amplifier 376 as a function of the DCvoltage generated by the gain control potentiometer 140.

[0078] In the towing vehicle-towed automobile system described above, abraking situation would occur as follows. Referring to FIGS. 1, 3, 4 and5, when the brakes of the towing vehicle are activated, controller 10receives an electrical signal from brake light line 36. The signal frombrake light line 36 is read by microprocessor 118 to indicate that abraking situation exists. Continually, while the towing vehicle is inoperation, microprocessor 118 is polling accelerometer 212 to determinethe base line acceleration of the vehicle and the forces due to gravity,or G forces. This polling is being done continually while there is nobrake light signal (i.e. whenever the towing vehicle is not in a brakingsituation). Because roads are rarely level and often roads go up or downhill, polling of the accelerometer gives the microprocessor a basis fordetermining the amount of force which must be applied. Thus, if thevehicles are traveling uphill and a braking situation occurs, themicroprocessor and accelerometer, which are continually determining Gforces, will not be fooled into believing that the towing vehicle isexerting greater braking power than it in fact is. Without such pollingof the current forces on the vehicles, application of the brakes by thebrake controller would be inaccurate, much like in the brake controllersof the prior art.

[0079] Upon receiving the brake light signal, microprocessor 118 pollsaccelerometer 212 to determine the amount of braking occurring, based onaccelerometer 212's reading of the instant change in the acceleration ofthe towing vehicle. Based on the information given by accelerometer 212,and a preprogrammed response in microprocessor 118, a control signal issent from control module 10 to power module 50. Microprocessor 264,within power module 50, senses the control signal and determines if itis within the acceptable range of control signals. Unacceptable signalscould otherwise be determined to be braking situations, for example, ifthere was a short circuit that caused a signal to be received in powermodule 50, microprocessor 264 would determine that signal was not anacceptable control signal and would not operate the braking systems ofthe towed vehicle.

[0080] Upon determination that the control signal is within theacceptable range, microprocessor 264 causes power module 50 to secureappropriate power, from the battery of the towed vehicle, so that anappropriate signal, representative of the control signal, may begenerated and sent to the actuator 86, which operates the brakes of thetowed automobile. Power module 50 also supplies power to a vacuum pump76 which allows appropriate brake pressure in the towed automobilewithout the necessity for the towed automobile to have either its enginerunning or the ignition set to the accessory position. Upondetermination that an appropriate braking signal has been received,power module 50 causes vacuum pump 76 to begin continuous operation forthe entire length of the braking situation. Upon the cessation of thebraking situation, power module 50 continues to cause operation ofvacuum pump 76 for a predetermined period of time, preferably 20seconds, to re-energize the vacuum of the braking system in preparationfor the next braking situation.

[0081] The power module 50 generates a signal on pin 72 to operate thevacuum pump 76, based upon the braking requirements. The vacuum pump 76is not the towed vehicle's own vacuum pump but it is a vacuum pump thatis supplied with the power module 50 and controller 10. Anytime abreakaway event occurs, a vacuum pump signal is generated. When there isa braking control signal on line 38, the vacuum pump 76 is operated solong as the braking signal continues. Once the braking signal stops, thesignal on pin 76 is continued for a predetermined amount of time,preferably twenty seconds, to replenish the vacuum pump 76 in order forit to be in condition to receive the next braking system on the controlline 38.

[0082] Note that the tow braking control signal is not a continuoussignal but is a pulse width modulated signal. The microprocessor 264 andthe power module 50 look for the sequence of pulses over an interval andso long as there are pulses occurring within that preprogrammed window,microprocessor 264 determines that the braking event is active. Thereception of such a signal causes the microprocessor 264 to run thevacuum pump 76 continuously, so as to provide a continuous source ofbraking power. However, even when control signals are not within thatwindow, microprocessor 324 maintains the vacuum pump for about 20seconds, as described above to provide braking power for the nextbraking situation. Thus when the pulse width modulated pulses stop,there are no longer any pulses at pin 82 and actuator 86 releases,releasing the brakes of the towed automobile. The vacuum pump 76 thencontinues for a predetermined time. Vacuum pump signal on pin 72 is nota pulse signal but is a continuous level signal.

[0083] In the towing vehicle-trailer system described above, a brakingsituation would occur in a manner similar to that in a towed automobilesituation. Referring to FIGS. 2, 3, 4 and 6, when the brakes of thetowing vehicle are activated, controller 10 receives an electricalsignal from brake light line 36. The signal from brake light line 36 isread by microprocessor 118 to indicate that a braking situation exists.

[0084] Upon receiving the brake light signal, microprocessor 118 pollsaccelerometer 212 to determine the amount of braking occurring, based onaccelerometer 212's reading of the instant change in the acceleration ofthe towing vehicle. Based on the information given by accelerometer 212,and a preprogrammed response in microprocessor 118, a control signal issent from control module 10 to power module 92. Microprocessor 324,within power module 92, senses the control signal and determines if itis within the acceptable range of control signals. Upon determinationthat the control signal is within the acceptable range, microprocessor324 causes power module 92 to secure appropriate power, from the batteryof the trailer or the towing vehicle, so that an appropriate amount ofpower, representative of the control signal, may be generated and sentto the electric brakes of the trailer.

[0085] When the system is not braking, microprocessor 118 is pollingaccelerometer 212 to determine the instantaneous gravitational forces,or G forces.

[0086] As noted above, both power module 50 and power module 92 produceand send a status signal to control module 10. The status signalproduced by power module 92 is responsive to the brake magnets'integrity. Thus if the brake magnets are not connected, there will be nostatus signal sent to the status LED 24 of the controller. The powermodule also sends the status signal to the control module with respectto the integrity of the trailer hitch so that if the trailer isdisconnected from the driving vehicle, there will be no signal and thestatus LED 24 will go out. A status warning alarm, in the form of buzzer180 (FIG. 3), will also sound if a breakaway condition exists, as willbe described below. The status signal produced by power module 50 isresponsive to the integrity of the power module.

[0087] The hitch socket plug 42 contains many other wires and connectorsthat couple the towed vehicle functions to the towing vehicle functions.For example, the brake lights and head lights and turn signals of thetowing vehicle are coupled to the respective parts of the towed vehicle.Thus when the brake of the towing vehicle is applied, the brake lightsof the towed vehicle and the towing vehicle will be energized. The powermodule 50 has a brake light switch 62 and 64 which is an interruptingrelay that disconnects the towed cars brake light switch from its taillights when there is a brake event. However, the brake lights of thetowed vehicle will still go on because it will be on as a result of therespective lines through the hitch. It can be seen that if the towedvehicle is disconnected from the towing vehicle and the breakaway switch58 is operated, the brake lights of the towed vehicle will go on as wellas the towed vehicle braking because the power module 50 has notreceived a proper braking signal sequence in effect telling the brakelight switch relay to interrupt. Referring back to the brake lightswitch, that is coupled to pins 62 and 64 through a relay. When thebrake control signal occurs during a braking event, that relay opens toopen the brake light switch circuit thereby cutting off the energizationof the brake light of the towed vehicle other than the towed vehicle'senergization resulting from the umbilical through the hitch.

[0088] It can be seen that a novel vehicle brake controller has beenprovided which can be used to accurately and safely help to control bothtowed automobiles and trailers, by enabling the driver of the towingvehicle to apply the brakes of towed vehicles.

[0089] Although illustrative embodiments of the invention has been shownand described, it is to be understood that various modifications andsubstitutions may be made by those skilled in the art without departingfrom the novel spirit and scope of the invention.

What is claimed is:
 1. A brake controller, for use with a towing vehiclewhen the towing vehicle is in association with a towed vehicle,comprising: a control module for location within the cab of the towingvehicle and comprising a user interface with manual braking controls andautomatic braking sensors; and, a power module, separate from saidremote control module, comprising power drivers for supplying power toactivate the brakes of the towed vehicle; said control module beingconnected to said power module such that when said control module isactivated the power drivers of said separate power module operate toactivate the brakes of the towed vehicle.
 2. The brake controller ofclaim 1, wherein said automatic braking sensors comprise a multi-axisaccelerometer for sensing acceleration forces on the towing vehicle. 3.The brake controller of claim 1, wherein said control module is adaptedto be mounted on one of the gear shift lever and dashboard of the towingvehicle.
 4. The brake controller of claim 1, wherein said power moduleis adapted to be mounted on one of the towing vehicle and the towedvehicle.
 5. The brake controller of claim 1, wherein said power moduleproduces and sends a status signal to said control module while saidcontrol module and power module are in electrical communication.
 6. Thebrake controller of claim 1, further comprising a visual warning systemto alert the user of the separation of the towed vehicle from the towingvehicle.
 7. The brake controller of claim 1, further comprising anaudible warning system to alert the user of separation of the towedvehicle from the towing vehicle.
 8. The brake controller of claim 1,wherein said power module comprises a breakaway switch such that uponthe separation of the towed vehicle from said towing vehicle the brakesof the towed vehicle are engaged.
 9. A brake controller, for use with atowing vehicle when said towing vehicle is in association with a towedvehicle, comprising; a control module for location within the towingvehicle and comprising a user interface with manual controls including again control knob, a manual control lever and automatic braking sensors;said control module producing a braking signal in the form of a pulsewidth modulated signal in response to a braking situation such that saidpulse width modulated signal is responsive to any one or combination ofthe length of time of said braking situation, the position of said gainknob, the position of said manual control lever and the forces read bysaid automatic braking sensors in response to said braking situation.10. The brake controller of claim 9, wherein said automatic brakingsensors comprise a multi-axis accelerometer for sensing accelerationforces on the towing vehicle.
 11. The brake controller of claim 9,wherein said control module is adapted to be mounted on one of the gearshift lever and dashboard of the towing vehicle.
 12. A brake controller,for use with a towing vehicle when said towing vehicle is in associationwith the a towed vehicle, comprising: a control module for locationwithin the towing vehicle and comprising a user interface with manualcontrols including a gain control knob and automatic braking sensorscomprising an accelerometer; a power module, separate from said controlmodule, for supplying power to activate the brakes of a towed vehicle;wherein manipulation of said gain control knob sets, through said powermodule, a static braking force and the action of said accelerometer onsaid power module adds a dynamic braking force in response to a brakingsituation.
 13. The brake controller of claim 12, wherein said automaticbraking sensors comprise a two or more axis accelerometer for sensingacceleration forces on the towing vehicle.
 14. The brake controller ofclaim 12, wherein said control module is adapted to be mounted on one ofthe gear shift lever and dashboard of the towing vehicle.
 15. The brakecontroller of claim 12, wherein said power module is adapted to bemounted on one of the towing vehicle and the towed vehicle.
 16. Thebrake controller of claim 12, wherein said power module produces andsends a status signal to said control module while said control moduleand power module are in electrical communication.
 17. The brakecontroller of claim 12, further comprising a visual warning system toalert the user of the separation of the towed vehicle from the towingvehicle.
 18. The brake controller of claim 12, further comprising anaudible warning system to alert the user of separation of the towedvehicle from the towing vehicle.
 19. The brake controller of claim 12,wherein said power module comprises a breakaway switch such that uponthe separation of the towed vehicle from said towing vehicle the brakesof the towed vehicle are engaged.
 20. A brake controller, for use with atowing vehicle when said towing vehicle is in association with the atowed vehicle, comprising: control circuitry for location within thetowing vehicle and comprising a user interface with manual controlsincluding a gain control knob and automatic braking sensors comprisingan accelerometer; power circuitry for supplying power to activate thebrakes of a towed vehicle; wherein manipulation of said gain controlknob sets, through said power circuitry, a static braking force andadjusts said power module's response to said accelerometer such that thebraking signal generated as result of forces read from saidaccelerometer is increased or decreased according to the manipulation ofthe gain control knob.
 21. The brake controller of claim 20, whereinsaid automatic braking sensors comprise a multi-axis accelerometer forsensing acceleration forces on the towing vehicle.
 22. The brakecontroller of claim 20, wherein said control circuitry is housed in acontrol module adapted to be mounted on one of the gear shift lever anddashboard of the towing vehicle.
 23. The brake controller of claim 20,wherein said power circuitry is housed in a power module adapted to bemounted on one of the towing vehicle and the towed vehicle.
 24. Thebrake controller of claim 20, wherein said power circuitry produces andsends a status signal to said control circuitry while said controlcircuitry and power circuitry are in electrical communication.
 25. Thebrake controller of claim 20, further comprising a visual warning systemto alert the user of the separation of the towed vehicle from the towingvehicle.
 26. The brake controller of claim 20, further comprising anaudible warning system to alert the user of separation of the towedvehicle from the towing vehicle.
 27. The brake controller of claim 20,wherein said power circuitry comprises a breakaway switch such that uponthe separation of the towed vehicle from said towing vehicle the brakesof the towed vehicle are engaged.
 28. A towed vehicle brake controllersystem, for use with a towing vehicle when the towing vehicle is inassociation with a towed automobile having a vacuum operated brakingsystem, comprising: power circuitry for producing a braking signal; and,a supplemental vacuum pump installed within the towed vehicle andconnected to said power circuitry, said vacuum pump operable in responseto a braking signal received from said power circuitry to providebraking force to said braking system; and, an actuator attached to thebrake pedal of the towed vehicle, and connected to said power circuitry,such that when said actuator receives a braking signal from said powercircuitry said automobile brake pedal is depressed.
 29. The brakecontroller system of claim 28, wherein said power circuitry causes theoperation of said vacuum pump upon receipt of a brake light signal andstops the operation of said vacuum pump after a predetermined timeperiod.
 30. The brake controller system of claim 28, wherein saidactuator is a solenoid.
 31. A towed vehicle brake controller system, foruse with a towing vehicle when the towing vehicle is in association witha towed vehicle, comprising: a control module, for location within thetowing vehicle and comprising brake situation sensors and control signalgenerators, said control signals comprising one or more codes; a powermodule comprising power drivers and a microprocessor for receivingcontrol signals and generating braking signals, said microprocessoradapted to sense control signals to determine if a received coderepresents a braking situation, and said power module generating abraking signal only in response to a code representing a brakingsituation.
 32. The brake controller of claim 31, wherein said automaticbraking sensors comprise a multi-axis accelerometer for sensingacceleration forces on the towing vehicle.
 33. The brake controller ofclaim 31, wherein said codes comprise one or more duty cycles.
 34. Thebrake controller of claim 31, wherein said control module is adapted tobe mounted on one of the gear shift lever and dashboard of the towingvehicle.
 35. The brake controller of claim 31, wherein said power moduleis adapted to be mounted on one of the towing vehicle and the towedvehicle.
 36. The brake controller of claim 31, wherein said power moduleproduces and sends a status signal to said control module while saidcontrol module and power module are in electrical communication.
 37. Thebrake controller of claim 31, further comprising a visual warning systemto alert the user of the separation of the towed vehicle from the towingvehicle.
 38. The brake controller of claim 31, further comprising anaudible warning system to alert the user of separation of the towedvehicle from the towing vehicle.
 39. The brake controller of claim 31,wherein said power module comprises a breakaway switch such that uponthe separation of the towed vehicle from said towing vehicle the brakesof the towed vehicle are engaged.
 40. A brake controller, for use with atowing vehicle when said towing vehicle is in association with the atowed vehicle, comprising: a multi-axis accelerometer adapted to sensingbraking forces on said towing vehicle and causing the activation of thebrakes of the towed vehicle.
 41. The brake controller of claim 40,wherein said multi-axis accelerometer reads forces on two axes.
 42. Thebrake controller of claim 40, wherein said multi-axis accelerometerreads forces on three axes.
 43. The brake controller of claim 40,further comprising a visual warning system to alert the user of theseparation of the towed vehicle from the towing vehicle.
 44. The brakecontroller of claim 40, further comprising an audible warning system toalert the user of separation of the towed vehicle from the towingvehicle.
 45. The brake controller of claim 40, further comprising abreakaway switch such that upon the separation of the towed vehicle fromsaid towing vehicle the brakes of the towed vehicle are engaged.
 46. Abrake controller, for use with a towing vehicle when the towing vehicleis in association with a towed vehicle, comprising: a control module forlocation within the towing vehicle and comprising a user interface withmanual braking controls, automatic braking sensors, and a status signaldisplay light; a power module, separate from said remote control module,comprising power drivers for supplying power to activate the brakes ofthe towed vehicle, said power module comprising a breakaway switch and astatus signal generator electrically connected to said signal displaylight; said control module being connected to said power module suchthat when said control module is activated power drivers of the separatepower module operate to activate the brakes of the towed vehicle; andsaid breakaway switch being operable to activate the brakes of the towedvehicle when the towed vehicle is separated from the towing vehicle. 47.The brake controller of claim 46, wherein said control module is adaptedto be mounted on one of the gear shift lever and dashboard of the towingvehicle.
 48. The brake controller of claim 46, wherein said automaticbraking sensors comprise a multi-axis accelerometer for sensingacceleration forces on the towing vehicle;
 49. The brake controller ofclaim 46, further comprising a visual warning system to alert the userof the separation of the towed vehicle from the towing vehicle.
 50. Thebrake controller of claim 46, further comprising an audible warningsystem to alert the user of separation of the towed vehicle from thetowing vehicle.
 51. A towed vehicle brake controller, for use with atowing vehicle when the towing vehicle is in association with a towedvehicle, comprising: a control module, for location within the towingvehicle and comprising a user interface comprising manual brakingcontrols, an accelerometer comprising acceleration force sensors, and amicroprocessor programmed to receive acceleration force data from saidaccelerometer and produce a braking signal in response thereto; a powermodule comprising power drivers, braking signal receptors and a poweramplifier in electrical communication with said microprocessor such thatwhen said microprocessor produces a braking signal, said power modulereceives said signal, and provides power to a towed vehicle brakesystem.
 52. The towed vehicle brake controller of claim 51, wherein saidbrake system of the towed vehicle comprises electronic trailer brakes.53. The towed vehicle brake controller of claim 51, wherein said brakesystem of the towed vehicle comprises an automobile braking systemsupplemented with a vacuum pump, to supply brake power, and an actuatorto depress the automobile brake pedal.
 54. The towed vehicle brakecontroller of claim 51 wherein said braking signal is a pulse widthmodulated signal.
 55. The towed vehicle brake controller of claim 51,wherein said control module is separate from said power module.
 56. Thetowed vehicle brake controller of claim 51, wherein said power module ismounted on a towed vehicle.
 57. The towed vehicle brake controller ofclaim 51, wherein said power module is connected to said control moduleby control wire.
 58. The towed vehicle brake controller of claim 51,wherein said manual controls include a gain adjustment knob forincreasing or decreasing braking power in the towed vehicle.
 59. Thebrake controller of claim 51, wherein manipulation of said gain controlknob sets, through said power module, a static braking force and theaction of said accelerometer on said power module adds a dynamic brakingforce in response to a braking situation.
 60. The brake controller ofclaim 51, wherein manipulation of said gain control knob sets, throughsaid power module, a static braking force and adjusts said powermodule's response to said accelerometer such that the braking signalgenerated as result of forces read from said accelerometer is increasedor decreased according to the manipulation of the gain control knob. 61.The towed vehicle brake controller of claim 51, wherein said powermodule produces and sends a status signal to said control module whilesaid control module and power module are in electrical communication.62. The towed vehicle brake controller of claim 51, further comprising avisual warning system to alert the user of the separation of the towedvehicle from the towing vehicle.
 63. The towed vehicle brake controllerof claim 51, further comprising an audible warning system to alert theuser of separation of the towed vehicle from the towing vehicle.
 64. Thebrake controller of claim 51, wherein said power module comprises abreakaway switch such that upon the separation of the towed vehicle fromsaid towing vehicle the brakes of the towed vehicle are engaged.
 65. Atowed vehicle brake controller, for use with a towing vehicle when thetowing vehicle is in association with a towed vehicle, comprising: acontrol module, for location within the towing vehicle and comprisingmanual braking controls including a gain control knob and a manual brakelever, an accelerometer comprising acceleration force sensors, and amicroprocessor programmed to receive acceleration force data from saidaccelerometer and produce a braking signal in response thereto; a powermodule comprising power drivers, braking signal receptors and a poweramplifier in electrical communication with said microprocessor such thatwhen said microprocessor produces a braking signal, said power modulereceives said signal, and provides power to a towed vehicle brakesystem; and wherein manipulation of said gain control knob sets, throughsaid power module, a static braking force and adjusts said powermodule's response to said accelerometer such that the braking signalgenerated as result of forces read from said accelerometer is increasedor decreased according to the manipulation of the gain control knob. 66.The brake controller of claim 65, wherein said power module comprises abreakaway switch such that upon the separation of the towed vehicle fromsaid towing vehicle the brakes of the towed vehicle are engaged.
 67. Thetowed vehicle brake controller of claim 65, wherein said brake system ofthe towed vehicle comprises electronic trailer brakes.
 68. The towedvehicle brake controller of claim 65, wherein said brake system of thetowed vehicle comprises an automobile braking system supplemented with avacuum pump, to supply brake power, and an actuator to depress theautomobile brake pedal.
 69. The towed vehicle brake controller of claim65, wherein said braking signal is a pulse width modulated signal. 70.The towed vehicle brake controller of claim 65, wherein said controlmodule is separate from said power module.
 71. The towed vehicle brakecontroller of claim 65, wherein said power module is connected to saidcontrol module by control wire.
 72. The towed vehicle brake controllerof claim 65, wherein said power module is mounted on a towed vehicle.73. A towed vehicle brake controller system, for use with a towingvehicle when the towing vehicle is in association with a towedautomobile having a vacuum operated braking system: control circuitry,for location within the towing vehicle and comprising manual brakingcontrols, an accelerometer comprising acceleration force sensors, and amicroprocessor programmed to receive acceleration force data from saidaccelerometer and produce a braking signal in response thereto; powercircuitry comprising power drivers, braking signal receptors and a poweramplifier in electrical communication with said microprocessor such thatwhen said microprocessor produces a braking signal, said power modulereceives said signal, and produces a representative signal; asupplemental vacuum pump installed within the towed vehicle andconnected to said power circuitry, said vacuum pump operable in responseto a braking signal received from said power circuitry to providebraking force to said braking system; and, an actuator attached to thebrake pedal of the towed vehicle, and connected to said power circuitry,such that when said actuator receives a braking signal from said powercircuitry said automobile brake pedal is depressed.
 74. The brakecontroller system of claim 73, wherein said power circuitry is housed ina power module and said control circuitry is housed in a control module.75. The brake controller system of claim 73, wherein said powercircuitry causes the operation of said vacuum pump upon receipt of abrake light signal and stops the operation of said vacuum pump at afterpredetermined time period.
 76. The brake controller system of claim 73,wherein said microprocessor produces a pulse width modulated brakingsignal and said representative signal from said power circuitry is apulse width modulated signal.
 77. The brake controller system of claim73, comprising a brake light cut off switch wherein the brake lights ofthe towed automobile are responsive to the braking of the towing vehicleand not the activation of the brakes of the towed vehicle.
 78. The brakecontroller system of claim 73, wherein said power circuitry produces andsends a status signal to said control circuitry while said controlcircuitry and power circuitry are in electrical communication.
 79. Thebrake controller system of claim 78, comprising a breakaway controlsystem wherein upon the said supplemental vacuum pump operatescontinually upon the cessation of said status signal and said powercircuitry causes a specific duty cycle in said actuator such that thetowed vehicle is stopped.
 80. The brake controller system of claim 73,wherein said actuator is a solenoid.
 81. A brake controller, for usewith a towing vehicle when the towing vehicle is in association with atowed vehicle, comprising: a control module for location within thetowing vehicle, connected to the ignition switch of the towing vehicle,and comprising manual braking controls and automatic braking sensors forproducing braking signals; and a power module, separate from said remotecontrol module, comprising power drivers for supplying power to activatethe brakes of the towed vehicle, connected to the brakes of the towedvehicle and a battery in the towed vehicle; said control module beingconnected to said power module such that only when said ignition of thetowing vehicle is on, said control module may produce and send brakingsignals to said power module which may then engage the brakes of thetowed vehicle.
 82. The brake controller of claim 81, wherein said powermodule is connected to said battery with heavy gauge wire and to saidcontrol module with lighter gauge wire.
 83. The brake controller ofclaim 81, wherein said control module to power module connection is alow power connection.
 84. The trailer brake controller of claim 81,further comprising a visual warning system to alert the user of theseparation of the towed vehicle from the towing vehicle.
 85. The trailerbrake controller of claim 81, further comprising an audible warningsystem to alert the user of separation of the towed vehicle from thetowing vehicle.
 86. The brake controller of claim 81, wherein said powermodule produces an electrical signal which illuminates a status light onsaid control module, such that the electrical separation of said controlmodule from said power module extinguishes said status light.
 87. Thebrake controller of claim 81, wherein said automatic braking sensorscomprise a multi-axis accelerometer for sensing braking forces in twoaxes of movement of the towing vehicle.
 88. The brake controller ofclaim 81, wherein said manual braking controls include a manual brakelever to allow the manual application of brake force proportional to theposition of said brake lever.
 89. A brake controller, for use with atowing vehicle when the towing vehicle is in association with a towedvehicle, comprising: a control module for location within the towingvehicle and comprising a user interface with manual braking controlscomprising a manual operated brake lever; and a power module, separatefrom said control module, comprising power drivers for supplying powerto activate the brakes of the towed vehicle; said control module beingelectrically connected to said power module such that when said brakinglever is depressed the brakes of a towed vehicle are engagedproportionally to the degree that the lever is depressed.
 90. Thetrailer brake controller of claim 89, wherein said power module producesand sends a status signal to said control module while said controlmodule and power module are in electrical communication.
 91. The trailerbrake controller of claim 89, further comprising a visual warning systemto alert the user of the separation of the towed vehicle from the towingvehicle.
 92. The trailer brake controller of claim 89, furthercomprising an audible warning system to alert the user of separation ofthe towed vehicle from the towing vehicle
 93. A method of applying thebrakes of a towed vehicle when it is in association with a towingvehicle including the steps of: providing a brake controller comprisinga control module and a separate power module, said control module beinghoused within the cab of the towed vehicle, said power module beinghoused in the towing vehicle; providing an accelerometer, amicroprocessor and a user interface with manual controls in said controlmodule, such that said control module can generate braking signals inresponse to braking situations in the towing vehicle; and providingpower drivers, a power amplifier and a microprocessor in said powermodule; connecting said control module and said power module, such thatbraking signals from said control module cause said power module toengage the brakes of the towed vehicle.
 94. The method of applying thebrakes of a towed vehicle of claim 93, including the step of providing amanual brake lever and a gain knob on said control module.
 95. Themethod of applying the brakes of a towed vehicle of claim 93, includingthe step of connecting said control module and said power module withcontrol wire.
 96. The method of applying the brakes of a towed vehicleof claim 93, including the step of connecting said control module to theignition switch of the towed vehicle and providing power to said brakecontroller when said ignition switch is turned on.
 97. A brakecontroller, for use with a towing vehicle when the towing vehicle is inassociation with a towed vehicle, comprising: control circuitry forsensing a braking situation and generating a control signal, saidcontrol signal comprising a multisequenced signal comprising two or morebraking level signals lasting the duration of the braking situation;power drive circuitry, in communication with said control circuitry, forreceiving control signals and generating braking signals to operate thebrakes of said towed vehicle.
 98. The brake controller of claim 97,wherein said braking level signals are of different brake power levels99. The brake controller of claim 97, wherein said braking level signalsare of different lengths of time.
 100. The brake controller of claim 97,wherein said braking level signals are of different brake power levelsand different lengths of time.
 101. The brake controller of claim 97,wherein said discrete braking level signals include a terminal brakingsignal lasting the duration of the braking situation.
 102. The brakecontroller of claim 97, wherein said multisequenced signal comprises aseries of predetermined braking periods.
 103. A brake controller, foruse with a towing vehicle when the towing vehicle is in association witha towed vehicle, comprising: control circuitry for sensing a brakingsituation and generating a control signal, said control signalcomprising a multisequenced signal comprising two or more braking levelsignals lasting the duration of the braking situation; a gain controlleradapted to change said control signal proportionally to the position ofsaid gain controller; power drive circuitry, in communication with saidcontrol circuitry, for receiving control signals and generating abraking signal to operate the brakes of said towed vehicle.
 104. Thebrake controller of claim 103, wherein increasing gain causes aproportional increase in brake power and decreasing gain causes aproportional decrease in brake power.
 105. The brake controller of claim103, wherein increasing gain causes a proportional increase in time ofbraking of the first of said braking level signals and decreasing gaincauses a proportional decrease in time of braking of the first of saidbraking level signals.
 106. A towed vehicle brake controller, for usewith a towing vehicle when the towing vehicle is in association with atowed vehicle, comprising: control circuitry, for location within thetowing vehicle and comprising manual braking controls including a gaincontrol knob and a manual brake lever, an accelerometer comprisingacceleration force sensors, and a microprocessor programmed to receiveacceleration force data from said accelerometer and produce a controlsignal in response thereto; said control signal comprising amultisequenced signal comprising two or more braking level signalslasting the duration of the braking situation; power circuitrycomprising power drivers, braking signal receptors and a power amplifierin electrical communication with said microprocessor such that when saidmicroprocessor produces a control signal, said power module receivessaid signal, and provides power to a towed vehicle brake system; andwherein manipulation of said gain control knob sets, through said powermodule, a static braking force and adjusts said power module's responseto said accelerometer such that the braking signal generated as resultof forces read from said accelerometer is increased or decreasedaccording to the manipulation of the gain control knob.
 107. The brakecontroller of claim 106, wherein said braking level signals are ofdifferent lengths of time.
 108. The brake controller of claim 106,wherein said braking level signals are of different brake power levelsand different lengths of time.
 109. The brake controller of claim 106,wherein said discrete braking level signals include a terminal brakingsignal lasting the duration of the braking situation.
 110. The brakecontroller of claim 106, wherein said multisequenced signal comprises aseries of predetermined braking periods.
 111. A brake controller, foruse with a towing vehicle when the towing vehicle is in association witha towed vehicle, comprising: control circuitry for sensing a brakingsituation and generating a control signal; power drive circuitry, incommunication with said control circuitry, for receiving a controlsignal and generating a braking signal to operate the brakes of saidtowed vehicle; wherein a break in communication between said controlcircuitry and said power drive circuitry causes said power drivecircuitry to produce a braking signal comprising a multisequenced signalcomprising two or more braking level signals lasting the duration of thebraking situation and engage the brakes of said towing vehicleaccordingly.
 112. The brake controller of claim 111, wherein loss ofcommunication is caused by a break-away condition.
 113. The brakecontroller of claim 111, wherein said braking level signals are ofdifferent brake power levels
 114. The brake controller of claim 111,wherein said braking level signals are of different lengths of time.115. The brake controller of claim 111, wherein said braking levelsignals are of different brake power levels and different lengths oftime.
 116. The brake controller of claim 111, wherein said discretebraking level signals include a terminal braking signal lasting theduration of the braking situation.
 117. The brake controller of claim111, wherein said multisequenced signal comprises a series ofpredetermined braking periods.
 118. A towed vehicle brake controllersystem, for use with a towing vehicle when the towing vehicle is inassociation with a towed vehicle, comprising: a control module, forlocation within the towing vehicle and comprising a status display; apower module, separate from said control module, comprising a statussignal generator; said status signal display being responsive to asignal generated by said status signal generator such that when saidpower module is operative, said status signal generator produces andsends a status signal which engages said status display.
 119. The brakecontroller of claim 118, wherein said status display is a light emittingdiode and said power module causes said light emitting diode to be litwhile said power module and control module are in electricalcommunication.
 120. The brake controller of claim 118, wherein saidcontrol module comprises an audible alert generator which emits an alarmwhen no status signal is received from said power module.
 121. The brakecontroller of claim 118, wherein said control module comprises anaudible alert generator which emits an alarm, for a predetermined timeperiod, when no status signal is received from said power module.
 122. Atowed vehicle brake controller system, for use with a towing vehiclewhen the towing vehicle is in association with a towed vehicle,comprising: a control module, for location within the towing vehicle andcomprising an audible alert generator; a power module, separate fromsaid control module, comprising a status signal generator; said audiblealert generator being responsive to a signal generated by said statussignal generator such that when said power module is operative, saidstatus signal generator produces and sends a status signal and when saidstatus signal is terminated said audible alert generator emits an alarm.123. The brake controller of claim 122, wherein said alarm terminatesafter a predetermined period of time.
 124. The brake controller of claim122, wherein said control module comprises a status signal light whichis lit when a status signal is received from said power module.
 125. Abrake controller, for use with a towing vehicle when the towing vehicleis in association with a towed vehicle, comprising: control circuitryfor sensing a braking situation and generating a control signal; powerdrive circuitry, including logic circuitry, in communication with saidcontrol circuitry, for receiving control signals and generating brakingsignals to operate the brakes of said towed vehicle, said power drivecircuitry comprising heat sensors such that when components of saidpower drive circuitry reach threshold temperatures said heat sensorscause said logic circuitry to interrupt said braking signals.
 126. Thebrake controller of claim 125, wherein said control circuitry is housedin a control module and said power circuitry is housed in a separatepower module.
 127. A brake controller, for use with a towing vehiclewhen the towing vehicle is in association with a towed vehicle,comprising: control circuitry for sensing a braking situation andgenerating a control signal; power drive circuitry, including logiccircuitry, in communication with said control circuitry, for receivingcontrol signals and generating braking signals to operate the brakes ofsaid towed vehicle, said power drive circuitry comprising heat sensorssuch that when components of said power drive circuitry reach thresholdtemperatures said heat sensors cause said logic circuitry to modulatesaid braking signals in proportion to said control signal and thetemperature of the heat sensors.
 128. The brake controller of claim 127,wherein components of said power drive circuitry are matched tocharacteristics of said brakes of said towed vehicle such that thresholdtemperatures in said power circuitry and said brakes occur at about thesame time in a braking situation.
 129. The brake controller of claim128, wherein said control circuitry is housed in a control module andsaid power circuitry is housed in a separate power module.